Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * hello_el2 - Basic KVM selftest for VM running at EL2 with E2H=RES1
4 *
5 * Copyright 2025 Google LLC
6 */
7#include "kvm_util.h"
8#include "processor.h"
9#include "test_util.h"
10#include "ucall.h"
11
12#include <asm/sysreg.h>
13
14static void guest_code(void)
15{
16 u64 mmfr0 = read_sysreg_s(SYS_ID_AA64MMFR0_EL1);
17 u64 mmfr1 = read_sysreg_s(SYS_ID_AA64MMFR1_EL1);
18 u64 mmfr4 = read_sysreg_s(SYS_ID_AA64MMFR4_EL1);
19 u8 e2h0 = SYS_FIELD_GET(ID_AA64MMFR4_EL1, E2H0, mmfr4);
20
21 GUEST_ASSERT_EQ(get_current_el(), 2);
22 GUEST_ASSERT(read_sysreg(hcr_el2) & HCR_EL2_E2H);
23 GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR1_EL1, VH, mmfr1),
24 ID_AA64MMFR1_EL1_VH_IMP);
25
26 /*
27 * Traps of the complete ID register space are IMPDEF without FEAT_FGT,
28 * which is really annoying to deal with in KVM describing E2H as RES1.
29 *
30 * If the implementation doesn't honor the trap then expect the register
31 * to return all zeros.
32 */
33 if (e2h0 == ID_AA64MMFR4_EL1_E2H0_IMP)
34 GUEST_ASSERT_EQ(SYS_FIELD_GET(ID_AA64MMFR0_EL1, FGT, mmfr0),
35 ID_AA64MMFR0_EL1_FGT_NI);
36 else
37 GUEST_ASSERT_EQ(e2h0, ID_AA64MMFR4_EL1_E2H0_NI_NV1);
38
39 GUEST_DONE();
40}
41
42int main(void)
43{
44 struct kvm_vcpu_init init;
45 struct kvm_vcpu *vcpu;
46 struct kvm_vm *vm;
47 struct ucall uc;
48
49 TEST_REQUIRE(kvm_check_cap(KVM_CAP_ARM_EL2));
50
51 vm = vm_create(1);
52
53 kvm_get_default_vcpu_target(vm, &init);
54 init.features[0] |= BIT(KVM_ARM_VCPU_HAS_EL2);
55 vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code);
56 kvm_arch_vm_finalize_vcpus(vm);
57
58 vcpu_run(vcpu);
59 switch (get_ucall(vcpu, &uc)) {
60 case UCALL_DONE:
61 break;
62 case UCALL_ABORT:
63 REPORT_GUEST_ASSERT(uc);
64 break;
65 default:
66 TEST_FAIL("Unhandled ucall: %ld\n", uc.cmd);
67 }
68
69 kvm_vm_free(vm);
70 return 0;
71}